Preparation of fibrous material



Aug. 11, 1936 E. OLSSON PREPARATION OF FIBROUS MATERIAL OriginaLFiled Nov. 6, 1 935 INVENTOR E/Is 0/5 01;

Y I K ATTORNEY Reissued Aug. 11, 1936 UNITED STATES PATENT OFFICE Original No. 2,006,559, dated July 2, 1935, Serial 7 No. 696,797, November 6, 1933. Application for reissue April 10, 1936, Serial No. 73,815

Claims.

This invention relates to the preparation of fibrous material for use in making paper products such as paper webs or sheets, cardboard or like products.

5 Pulp is usually digested by low pressure steam and suitable treating liquor and is then discharged from the digester, washed and ground to the desired fineness. These operations require a considerable amount of time.

. This invention has for its salient object to provide apparatus for treating fibrous material so constructed and arranged that the time required 'Qfor the treatment will be materially reduced.

Another object of the invention is to provide an apparatus of the character described so con- .structed and arranged that high pressure used in the digester 'can be utilized to force the material through the grinder'or pulverizer.

A further obiect'oi' the invention is to provide a process of treating ilbrous material so worked out that the pressure from the digester is utilized .to force the material through the grinding mechanism.

Further objects of the invention will appear from the followingspeciflcation taken in connection with the drawing which forms a part of this application, and in which Fig. 1 is a diagrammatic elevational view showing apparatus constructed in accordance with the invention;

Fig. 2 is an enlarged detail sectional elevation skewing the grinding-imechanism;

Fig. 3 is atop plan-view of one of the grinding digester into which high pressure steam is introduced and having adischarge outlet through which the digested material and liquor are discharged or blown when the material has been sufliciently digested. The discharge outlet of the digester is connected by a conduit to the grinding apparatus, the digested material being conducted through the conduit by the force of the high pressure in the dig ter and being forced between the grinding elements. The digester operation is very materially shortened by the use of the high pressure steam and the use of this steam 50 to force the material through the grinding mechanism further reduces the time required for carrying out the treatment of the fibrous-material.

Further details of the invention will appear 5 from the following description.

In the particular form of apparatus illustrated in the drawing there is shown diagrammatically in Fig. 1 a digester D having an inlet opening Ill which is connected to a source of high pressure steam and a charging opening ll through which 5 the fibrous material to be digested is received. The digestcr also has a discharge opening I! vwhich is connected by a conduit iii to a plate H which forms asupport for one of a pair of grinding plates IS. The other plate I6 is supported by 10 a supporting plate IT in a position above the plate IS. The plate support I! is carried by a shaft I8 having thrust supporting bearings l9 and extending upwardly through the thrust bearings to drive transmitting mechanism 20 which is connected to a motor M by a shaft 2|. The upper grinding plate it is thus positively driven by the motor and the lower plate is shown as stationary, although if desired this plate may also be rotated but in a direction opposite to the direction of rotation of the plate II. The plate I! has a central opening through which the material is fed and the upper plate II has a central dome 26. The plates are preferably spaced slightly apart, the amount of spacing being de- 25 :rmined by a vertical adiustment of the upper ate. v

The grinding plates may be of any suitable construction but are preferably serrated o roughened, as shown in Fig. 3.

The grindingmechanismishousedina casing I0 and bailiewplates it -rand Share disposed on opposite sides of the grinding The plate support I4 is mounted on a bracket 38 carried by a frame member 34. A vent pipe 3! extends upwardly from the cas ng or tank III to relieve the pressure in the tank or casing.

The casing III has an outlet opening it at the bottom thereof which is connected by a conduit 3'! tea diffuser or washing mechanism 38 having adischarge opening is and an outlet conduit 4! through-which the-liquid can escape from the diffuser.-

- Operation After the digester has been charged and the material therein has been treated under high pressure for a relatively short time the discharge outlet I2 is opened permitting the treated material to be forced under the high pressure in the digester through the conduit l3 to the grinding mechanism and outwardly between the grinding plates l5 and ii. By these plates the material is ground or pulverized to the desired extent and passes through the outlet opening II of the cas- 55 prising a digester, means for supplying high pre'sing "and through the conduit 31 into the diffuser where it is washed. I

From the foregolng description it will be evident that the apparatus described will effectively and expeditiously treat fibrous material.

By the use of this process and apparatus the time normally required for the digestion of the pulp isimaterially cut down'or reduced since partialdigestion-is sufllcient and complete digestion is unnecessary.

Although one specific embodiment of the invention has been 'particularly shown and described it will be understood that the invention is capable of modification and that changes in the construction and in the arrangement of the various cooperating partsmay be made without departing from the spirit or scopeof the inv'ention, as expressed in the following claims.

What I claim is:

1. Apparatus for treating fibrous material comprising a digester means for supplying high sure steam thereto, said digester having a discharge outlet, a pulp receiving chamber, a grinder.

mounted in said chamber and comprising a pair of grinding plates, arranged to coact and grind the material, a conduit arranged to conduct the mechanism when the digester material from the digester outlet after the material is digested to a position between the central portions of said plates, the material being forced through said conduit and outwardly between said plates by the pressure in the digester when the 5 discharge outlet is opened, and means for rotating one of said grinding plates 3. Apparatusjfor treating fibrous material comprisinga digester, means for supplying high pressure steam thereto, said .digester having a dis- I0 charge outlet, apulp receiving chamber, a grinder mountedin said chamber and comprising a pair of spaced elements disposed above the level of the discharge outlet and arranged to coact and grind the material, a conduit arranged to conduct the 15 matenalfrom'the digester outlet after the material is digestedto a position between said elements,

the material being forced through said conduit and between said elements by the pressure in the digester when the discharge outlet is opened, and 2 means forrotating one of said grinding elements.

4. Apparatus iortreating fibrous material comprising a digester having a discharge outlet, means for supplying high pressure steam thereto, a pulp chamber, a pair of grinding platesthereln, one 25 plate having an opening for receiving the material tobe ground, a, conduit for conducting the treated material from the digester outlet after the material is digested to said opening, thepressure in the digester forcing the material through said 30 conduit to the grinding plates, and means for rotating one of said plates. g

5. The process. of treating fibrous material which consists of digesting the material under high pressure and utilizing the digester pressure 35 to force the material to and through grinding charge is blown from the'digester.

l ELIS oLssoN. 

